Piston with a ring carrier and a glass piston

Patent metadata

Field	Value
Publication number	US-9828937-B2
Application number	US-201414899641-A
Country	US
Kind code	B2
Filing date	Jun 5, 2014
Priority date	Jun 19, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

The invention relates to a piston ( 1 ), comprising a ring carrier ( 2 ) and a glass piston ( 3 ) for observing processes in a combustion chamber (B) of an internal combustion engine, wherein the glass piston ( 3 ) is placed upon the ring carrier ( 2 ) and is securely connected thereto in the region of an inner casing surface ( 8 ) of the ring carrier ( 2 ). In order to avoid overly high heat strain in the glass piston ( 3 ), the glass piston ( 3 ) is connected to the ring carrier ( 2 ) via at least one form-fit connection ( 20 ), and preferably via a force-fit connection ( 30 ).

First claim

The invention claimed is:

1. A piston having a ring carrier and a glass piston for observing procedures in a combustion chamber of an internal combustion engine, wherein the glass piston is placed on the ring carrier and is fixedly connected thereto in a region of an inner lateral surface of the ring carrier, wherein the glass piston is connected to the ring carrier via at least one form-fit connection, wherein the glass piston rests on its gas-pressure-averted rear on at least one expansion ring, which is supported via at least one counter holder element on the ring carrier, wherein the counter holder element is formed by a counter screw connection, which is detachably connected in a friction-locked manner to an inner lateral surface of the ring carrier.

2. The piston according to claim 1 , wherein the glass piston is connected to the ring carrier via at least one form-fit connection and is connected via a friction-locked connection, which is detachably connected in a friction-locked manner to the inner lateral surface of the ring carrier.

3. The piston according to claim 2 , wherein the friction-locked connection is formed by the at least one fastening ring and the ring carrier.

4. The piston according to claim 3 , wherein the friction-locked connection has an external thread on the outer lateral surface of the fastening ring and a corresponding internal thread of the inner lateral surface of the ring carrier, wherein the fastening ring is screwed via the external thread into the internal thread of the ring carrier.

5. The piston according to claim 1 , wherein the form-fit connection is formed by the glass piston and at least one fastening ring.

6. The piston according to claim 5 , wherein the fastening ring is integrally formed.

7. The piston according to claim 5 , wherein the fastening ring is severed at at least one point.

8. The piston according to claim 7 , wherein the fastening ring is severed completely.

9. The piston according to claim 5 , wherein the fastening ring is formed by at least two ring segments which are connected to one another in the region of joining faces facing toward one another.

10. The piston according to claim 9 , wherein said at least two ring segments are connected to one another via at least one connection pin arranged in boreholes of the joining faces.

11. The piston according to claim 9 , wherein the fastening ring is connected in a rotationally-fixed manner to the glass piston.

12. The piston according to claim 1 , wherein the rotationally-fixed connection is formed by an adhesive bond or a further form-fit connection.

13. The piston according to claim 5 , wherein the fastening ring consists of aluminum.

14. The piston according to claim 1 , wherein the form-fit connection has at least one circumferential groove in a region of an outer lateral surface of the glass piston, in which the fastening ring formed reciprocally corresponding to the circumferential groove is arranged.

15. The piston according to claim 14 , wherein the circumferential groove is embodied as a wedge groove, so that in the event of a thermal expansion of the fastening ring, a friction-locked connection to the ring carrier is maintained.

16. The piston according to claim 15 , wherein the wedge groove has first and second wedge faces facing toward one another, wherein the first wedge face has a lesser distance to a gas-pressure-side front of the glass piston than the second wedge face.

17. The piston according to claim 16 , wherein the first wedge face spans a first wedge angle with a normal plane on the piston axis of the piston, wherein the first wedge angle is between approximately 30° and 70°.

18. The piston according to claim 17 , wherein the first wedge angle is between 40° and 60°.

19. The piston according to of claim 1 , wherein the glass piston has a ring-shaped projection, wherein a ring-shaped contact surface arranged perpendicularly to the piston axis is formed in the region of the projection.

20. The piston according to claim 19 , wherein the contact surface rests on a frontal ring front of the ring carrier.

21. The piston according to claim 20 , wherein the at least one seal element, particularly preferably a silicone seal, is arranged between the glass piston and the ring carrier.

22. The piston according to claim 21 , wherein the said least one seal element is a silicone seal.

23. The piston according to of claim 19 wherein the ring-shaped projection adjoins the circumferential groove on the combustion chamber side.

24. The piston according to claim 1 , wherein the expansion ring consists of aluminum.

25. The piston according to claim 1 , wherein the counter holder element is formed by a shoulder protruding from the inner lateral surface of the ring carrier.

26. The piston according to claim 1 , wherein the ring carrier is formed as a cylindrical element, which is embodied as internally hollow, having an inner lateral surface and an outer lateral surface.

27. The piston according to claim 1 , wherein the glass piston has a gas-pressure-side, first glass piston portion, which is adjoined on the side facing away from the combustion chamber, by a second glass piston portion, wherein the first glass piston portion protrudes on the gas-pressure side out of the ring carrier and the second glass piston portion is located inside the ring carrier.

Assignees

• Avl List Gmbh

Inventors

• Winklhofer Ernst
• Huber Christopher
• Neumann Franz

Classifications

• F02F3/0084 Primary

  the pistons being constructed from specific materials · CPC title

• F02F3/0015

  Multi-part pistons · CPC title

• F02F3/285

  the head being provided with an insert located in or on the combustion-gas-swept surface · CPC title

• F16J1/01

  characterised by the use of particular materials (F16J1/02 takes precedence) · CPC title

• F16J1/006

  of different materials · CPC title